Filters



June 14, 1960 G. McLElsH COLLINS FILTERS 3 Sheets-Sheet 1 Filed DeG. 3, 1956 /IV VE/V 701@ LJ, Ouml..

ATTaRA/H/S June 14, 1960 G. McLElsH coLLlNs 2,940,596

FILTERS Filed Dec. 3, 1956 l 5 Sheets-Sheet 2 VVE/V70@ LA? kwam. YM (man.

ATTOE/VEY June 14, 1960 G. MCLEISH coLLlNs 2,940,596

FILTERS Filed D60. 3, 1956 PES4.

Arme/V92 3 Sheets-Sheet 3 United States Patent O FILTERS George McLeish Collins, Birmingham, England, assignor to The Birmingham Small Arms Company Limited,

This invention relates to filters of the kind in which porous metal filter elements are disposed more or less lradially around and in communication with a substantially central tube.

In filters of this kind the elements are frequently secured in their assembled form by welding each one at one end to a header chest or chamber or by welding both ends to header chests or chambers which in turn are secured to and communicate with the central tube. There are drawbacks to such constructions, one being that Welding of the filter element by orthodox welding methods invariably causes oxidation of the lter element near the weld. To minimize the adverse elects of oxidation it is necessary or desirable to treat the assembled unit in a reducing furnace at high temperature and, among other things, this tends to cause distortion. Another'drawback is that the replacement of damaged filter elements is not easy and again involves welding of the elements with consequent reducing-furnace treatment.

lt is one of the objects of this invention to provide a filter of the kind referred to in which the elements may be more easily replaced.

According to the invention, a filter of the kind referred to comprises iilter elements from which extend tubes which are secured to a header chest or directly to the said central tube, the lter element tubes being sufficiently accessible to permit of any necessary replacement of an element or elements.

Each filter element may be replaceable by cutting the tubes connecting it to the header chest or central tube and securing the tubes of a fresh lter element to the portions of tube remaining in the header chest or central tube.

Alternatively, the said filter element tubes may each be provided with a detachable coupling for example, a screwed union, for enabling replacement of an element or elements to be eiected Without the necessity for cutting and resecuring tubes.

The header chest, where provided, and the central tube are preferably circular in cross-section and preferably less in diameter than that of the circle joining the inner edges of the lter elements.

Where the iilter element tubes are connected directly to the said central tube, the central tube may be enlarged in diameter at or near the position or positions where the filter element tubes are connected to it. Alternatively, the enlarged diameter of the central tube may continue over the whole of its effective length adjacent the filter elements.

The filter element tubes preferably extend from the ends of the filter elements. The ends conveniently may be plates of non-porous metal, selected plates each having a suitable hole for accommodation of the respective tube which is secured to the end plate, for example by welding.

The iilter elements are preferably of hollow construction and each comprise two curved porous metal plates "ice secured together along their two longitudinal edges, for example by welding, with the said end plates secured to the ends of the porous plates to form an enclosure with which the said tubes communicate. j

Each lter element is preferably reinforced either internally or externally by a supporting structure of nonporous material. Where the supporting structure is internal and has a member or members which extend com-V pletely across the enclosure, those members have apertures for permitting the passage of tiuid within the enclosure.

The filter element tubes may be secured to the header chest or the central tube in a staggered manner so as to allow of the provision of more lter elements than otherwise would be possible where the diameter of the header chest or central 4tube is limited.

ln the accompanying drawings-'- Figure 1 is a side view, partly in section on line l-I of Figure 2, of a filter according to the invention,

Figure 2 is a plan view thereof, partly in section online lil-lil of Figure l,

Figure 3 is a perspective view of the filter Figure 4 is a side elevation of a detail and illustrates another construction,

Figure 5 is an end elevation of Figure 4,

Figure 6 is a fragmentary side view in medial section of a detail and illustrates a further construction,

Figure 7 is a fragmentary side view in medial section of a detail and illustrates still another construction, j

Figure 8 is a similar view to Figure 7 and illustrates a still further construction, and

Figure 9 is a fragmentary side elevation of a detail and illustrates yet a further construction.

Referring to the drawings, in the construction shown in Figures 1, 2 and 3 thereof, as applied by Way of example to a filter comprising an assembly 1 of 'llter elements generally indicated by the reference numeral 2 disposed more or less radially around a substantially central tube 3, the filter elements 2 each communicates with header chests 4, 5 respectively, and each header chest communicates with the central tube 3. Each iilter element 2 consists of two curved porous metal (for example stainless steel) plates 6, 7 respectively, welded together along their two longitudinal edges and having non-porous end plates 8, 9 welded to them at their respective ends, the plates 6, 7, 8, 9 together forming the walls of an enclosure 10. A supporting structure 11 for each element 2 consists of two longitudinal members 12 arranged at right angles to a plane radial to the central tube 3 and passing through the respective elements, two longitudinal members 13 disposed in the said plane and each secured to the plates 6, 7 by the respective Weld joining the plates 6, 7, four spacing members 14, two being disposed adjacent each end plate of the element 2 in the said plane and welded to the members 12 and 13 -to extend between them, and three further spacing members 15 which are U-shaped and welded to and disposed between the two members 12,

one adjacent each end plate of the respective elements.

and the remaining one midway between the end plates. Each supporting structure 11 serves to reinforce the respective filter element. The members of the supportingv chest 4, S so as to be in communication with the interior` thereof. The ends of the central tube 3 project beyond the header chests 4, 5 andare screw-threaded 'tor-en- Y abling them to be secured to lead-in and lead-out pipes,

not shown, in usual manner. Y Y

The tubes 17, 18 are bent inwardly with as gradual a curveIas possible to avoid pressure losses. The external diameterofthe header chests 4, Sis made less than the tral'tube 34 issubstantially similar to that of the v'header lterelements 2, for `instance during a cleansing reverse flow .through the lfilter, there is a minimum of projecting surfaces .on which .the particles can lodge. This is of some importance 'where a .double ended header chest construction is Vemployed in certain exothermic catalytic processes Where .the heatV generated by the reaction from anaccumllliation of .catalyst may be suicient to have Van adverseletfect upontheconstructioni Y To replaceanelement 2 the tubes 17, 18 are sawed or otherwise 4cut at any suitable point, the element removed, a fresh element, having a suitable length of tube secured thereto, is placedin position and the two portions of tube Vwelded, brazed, soldered or otherwise Ysecured together It may beimentioned here that .as `the tubes are solid, Le. non-porous, oxidation elects will beY much less'than in the case ofporouszmetal and mayin mostcases be disregarded.v Y Y In'anotherconstruction, shown in Figures 4 and 5, a

Y supporting .structure .19.tor each element 20, one of which the memberszl. Otherwise the .construction is similar 'to that described with reference .to Figures 1 to 3.

Ima third construction, illustrated in Figure v6, thereonstrlction is similar to that described with reference to Figures l Ito v3 or that described with reference to Figures4land 5, except that :each :tube (one of which is illustrated in Figure .6 and `designated 26V) is in `two parts 27,

. 28lrespectively, which are connected, and can be disconnected to .elect ,replacement of a lilter element, by a screweduuion 29 of :known kind. This construction has the #advantage .that replacement of fan element can be` evectednuickly .and .easily without Ythe necessity for cuttingftubes and the subsequent welding or the like re-V quired for the connectionof Va fresh element.

' YIn `a .fourth construction, Vshown in*v Figure 7, each header chestone of which .is shown in Figure 7 Vanddesignated, instead of'being separate from and secured;

toa 'central' tubeis .formed by a part of the vcentral tube 3.1 itself, the part ybeing of enlarged diameter at the position required. Tubes 32 .are secured to the header chest in Vsimilar manner to that described with reference to Fig- Y scnibedwithreferenceto .Figure-7, tubes 33 fromthe filter elements (not shown) are secured to and communicate directly acentral tube 34-which'is of enlarged diameter compared with the ,central Vtube 3 .of the construction described with reference to Figures l to 3 except at Y itsends `(one ofywhich is shown in Figure '8 and desig- Hated 3'5) which are screwthreade'd and of'similar dianreter'rtorthe'ends 'of the central pipe 3 of the said construction. The enlarged diameter part vof the jcentnalftube 34/thereforefforms one continuous header Vchest extendvoverInoregthan the whole length of the assembly of litter-elements. 'Alhefdiameterof the said part Lof the cenchests 4, 5 of the said construction and is similarly less than the diameter of the circle joining the 'inner edges of the iilter elements. The remainder of ythe construction is similar to the said construction or to that described with reference to Figures 4 and 5, or to that described with reference to Figure-.6.` n

ln a construction alternative to that described with reference to Figure 8, `there .Pis Villustrated in Figure 9 a construction wherein tubes 36 from filter elements .37 (three of vwhich .are .shown in'Fgure 9) :are secured directly to and communicate with a central tube-38 `which is not of enlarged diameter at any part Yof its length. In order not to restrict the number of ltubes 36 lby virtue of the smallness of diameter of the tube 38the tubes -36 are staggered as shown in Figure 9. Y The yremainder of the construction isY similar .to that describedwith reference to Figures 1 to 3, or thatrdescribedwith reference to Figures 4 -and 5, or that described with reference to Figure 6.

it will be appreciated that all constnuctions ydescribed hereinhave in commonzthe advantage that in replacement of lter elements oxidation of the porous 4parts of the lilter is avoided, and consequently the necessity Vfor subsequent Vreduction treatment, which can lead vtofdistoriion, is eliminated.

I claim:

l. A Vfilter comprising azcentral tube, hollow filter elements :arranged radially around said central tube, Ieach hollow lterelement having opposed porous Vmetal :side plates and non-porous metal end plates dening an enclosure with said side plates, andluid communication tubes welded V.at one end to said non-porous'metal end plates and fixed at their outer ends to said central tube and providing communication between said-enclosures of the lter elements and said central tube.

2. A filter comprising an assembly of hollow porous metal ilter elements'arranged Vradially around a central tube in spaced relation thereto, each hollow lter element having porous metal side walls and non-porous metal end walls having apertures-and delining an enclosure ywith said side walls, a header Vchest ateach end of said central tube and in iiuid communication therewith, and tubes connected at opposite ends to said-header chests vand saidY non-porous end walls of'said lterY elements and `extending into associated-ones' of said yapertures tor providing iuid communicationbetween therinteriors of the lter elements and Vsaid rcentral-tube, Aportions of said connecting tubes being accessible for effecting individual removal and replacement of the respective filter elements by cuttingsaid connecting tubessandsecuring of the tube portionsof fresh` lilterV elements tothe tube vportions remainingin communication `with the'header chestrofvsaid cent1-al tube, A

f 3. A lter `comprising a central tube, hollow Iilter elements arranged radially around Vvsaid centralftube, Aeach lter element comprising two outwardlyr'curved 'porous metal plates secured together-along opposite longitudinal edges thereof, and opposed non-porous metal end plates secured to the ends of said curved plates,1said vcurved plates and end plates together defining an enclosure within thev plates, and filtered medium fluid Ycommunication` tubes for each vfilter element, each of said tubes engaging an aperture in an end plate tor uidcommunication with the respective enclosure, vand each tube also communicating with said centraltubefor establishing iluid Ycommunication between the respective enclosure and said central tube.Y i

4. A filter according to claimV 3, including reinforcement meansfor reinforcing said lhollow-lilter elements.

5. A iilterV according to Yclaim 3, including external reinforcement means for reinforcing lsaidfho'llowfilter elements. Y 6. A lter comprising a central tube, hollow iilter elements arranged yradially around said central tube, each lter element comprising two reversely curved porous metal plates secured Itogether along longitudinal edges thereof, and two non-porous metal end plates having apertures therein and secured to the ends of said curved plates, said curved plates and end plates together dening an enclosure within said plates, reinforcement means for internally reinforcing said hollow -lter elements and comprising at least one non-porous member extending across the enclosure of the respective lter element and having at least one aperture therein for the passage of uid therethrough to all parts of said enclosure, and ltered medium uid communication tubes providing communication between the enclosures of the respective lter elements and said central tube and Welded to associated ones of said end plates in surrounding relation to said apertures therein.

7. A filter comprising a central tube, hollow filter elements arranged radially around said central tube, each hollow lter element comprising porous metal side plates and non-porous metal ends, and inlet and outlet tubes for connecting the ends of the respective filter elements to said central tube and providing communication between the interiors of said lter elements and said central tube, said tubes extending radially outwardly from said central tube in staggered relationship and being curved to meet said filter elements in directions parallel to the axis of said central tube.

References Cited in the le of this patent UNITED STATES PATENTS 767,808 Forbes Aug. 16, 1904 967,776 Huber Aug. 16, 1910 1,193,334 Aeheson Aug. 1, 1916 2,394,076 Kisch Feb. 5, 1946 2,406,065 Dickinson et al Aug. 20, 1946 FOREIGN PATENTS 62,360 Germany June 28, 1891 10,984 Great Britain Dec. 8, 1845 

